Compressor



Feb. 25, 1936. w. D. DRYSDALE 2,031,940

COMPRESSOR Filed Aug. 9, 19:2 4 Sheets-Sheet 1 v TQM $.D3 @2029, b rjuwwzt I M6 Feb. 25, 1936. w. D. DRYSDALE -COMPRESSOR Filed Aug. 9, 1952 4 Sheets-Sheet 2 M dizzy-s Feb. 25, 1936. w. D. DRYSDALE 2,031,940

COMPRESSOR Filed Aug. 9, 1932 4 Sheets-sheaf. s

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W. D. DRYSDALE COMPRESSOR Filed Aug. 9, 1952 4 Sheets-Sheet 4 i will be pointed out more Patents Fe. 25, 1936 2,031,94 CORESSOR William ID. Drysdale, Buflalo, N. 322,

assignor to Walter J. Sugden, Boston, Application August 9, 1932, Serial No. 628,037 23 Claims. (or. 230-206) This invention relates to motor-driven compressors suitable for refrigerating machines of the compressor, condenser, expander type, and is more especially concerned with a compressor having a novel and improved oiling system for lubrieating the various bearing surfaces, removing oil from the motor chamber and separating the oil from the gas, before the latter reaches the compressor cylinder.

I embodying the invention;

Fig. 2 is a vertical, longitudinal section on an enlarged scale, mostly on line 2-2 of Fig. 1;

Fig. 3 is a vertical, sectional view on line 3-3 of Fig. 2;

Fig. 4 is a vertical, d6 of Fig. 2;

sectional view, partly on line Fig. 5 is a vertical, sectional view on line 55 of Fig. 2;

Fig. 6 is a vertical, sectional view on line 6-6 of Fig. 2;

Fig. '7 is a perspective view of a baflle which assists in separating the oil from the refrigerant and prevents oil from entering the compressor cylinder;

' Fig. 8 is a plan, on an enlarged scale, of a sliding shoe. or cross-head, which connects the crankpin to the piston,"

Fig. 9 is a horizontal, 9-9 of Fig. 6; I

Fig. 10' is a horizontal, sectional view of the main bearing on line III-l0 of Fig. 3; and

Fig. 11 is a vertical, sectional view, on line Hl| of Fig. 10.

Referring to the drawings, and to the embodiment of the invention illustrated therein, and having reference at first more particularly to Fig. 6, there is shown a cylinder having a lateral intake port 2 I, which is covered and uncovered by a piston 22. The charge drawn into the cylinder and compressed by. the piston is discharged through openings 23 in a plate 24 having an annular seat 25 for an outlet valve 26, which, as shown, is a thin, wafer-like steel disk, normally urged to its seat by a spring 21 within an outlet chamber 28, formed in a cylinder head 29, and communicating with an outlet passage 30, the latter in practice being connected with a condenser,

sectional view, on line In the present example, the cylinder 20 is in the nature of a. sleeve or lining, fixedly mounted in a surrounding support, herein a housing 3 I, having a chamber 32, which encloses part of the driving mechanism.

The driving mechanism, as herein shown, comprises an element such as a crank-pin 33, having an orbital path, and suitably connected to the piston to reciprocate the latter, the connection shown being a shoe or cross-head 34, mounted to m slide in a groove extending transversely of the piston, though the invention is not limited to this form of driving connection, but. might employ, for example, a connecting rod or pitman.

Turning now to Fig. 2, the crank-pin isdriven' 15 by a rotatable element, herein a shaft 36 mounted to rotate in a bearing 31- presented by a plate 38, which is in the nature of a wall constituting a. cover for the chamber 32, and a partition which separates the latter froma motor also formed in the housing 3!, the other end of this motor chamber being closed andsealed by a cover plate 30, thus providing a sealed housing for the entire mechanism. 'Ihe plate 38 is suitably secured in place, as by cap-screws ll, and 25 the plate 40 is similarly secured screws 42.

The motor chamber 39 houses an electric motor comprising a stator 43 fixed in the housing, and a in place by caprotor M suitably secured to the shaft 36, as by 30 providing the latter with a reduced portion 45, to which the rotor is secured as by a key 36 and by a nut 61 threaded onto a further reduced portion 58 The nut urges the rotor and a suitable thrust washer 49 toward a. shoulder 50 presented 35 by the body of the shaft, said washer resting against the adjacent end of the bearing 37, while running. The rotor is slightly oflset axially with relation to the stator in a direction opposite to the bearing, thereby to utilize the magnetic flux to to eliminate any tendency of the rotor to move endwise. The stator has three lead wires 5|, attached respectively to lead-in plugs 52, two of which are shown in Fig. 1.

The refrigerant to be compressed, instead of entering the chamber 32 directly, enters the mo tor chamber 39, as by means of a plug 53 (see Fig. 1), threaded into the housing, said plug in practice being connected as usual with an expander. The refrigerant, after entering the mo tor chamber 39, enters the lower end of a conduit (see Fig. 2) formed partly by a pipe 54 and partly by a passage 55 (see Fig. 4) and a passage 56, both drilled in the cover-plate 38, into a recess 51 .(see Fig. 3), which is in efiect a part or the 55 chamber 31, go

, passages 58 and 59 drilled in the casing 3|, and thence through a port 60 in registration with the lateral intake port 2| of the cylinder 20. Thus, the refrigerant, on its way to the cylinder, passes through the motor chamber, and cools the motor as well as the shaft and its bearing.

So far as the general aspects of the oiling system presently to be described are concerned, the crank-pin 33 might be fixedly secured to the driving shaft 36. In the form shown, however, the crank-pin 'is connected to the driving shaft by unloading mechanism (see Fig. 2), which in general may be said to impart to the piston a reciprocatory motion of variable amplitude, varying from a zone in which the piston covers and uncovers the lateral intake port and. causes gas to be admitted through said port and discharged past the outlet valve, to a zone within which the piston maintains the port closed. In the first zone, a full stroke is imparted to the piston, while in the second zone, the stroke is reduced to one of small amplitude, or if desired, may be reduced to zero. In the form shown, the stroke is reduced to one of small amplitude, the amount of reduction of the stroke being determined by the amount of eccentricity of the oscillatory elem'ent now to be described.

The crank-pin which has been referred to as an element having an orbital path is carried by an oscillatory element, herein a rockshaft 6!,

having an axis of oscillation eccentric to the axis of rotation of the rotatable element, namely: the shaft 36. When, therefore, the rockshaft is turned about its axis, the radius of the orbit of the crank-pin is varied from a radius in which the piston is effective to cover and uncover the lateral intake port of the cylinder to a radius in which the piston is ineffective to uncover said port, and furthermore, this change of radius changes the load of the compressor on the motor from full load in which the piston is at full stroke to a reduced load, or no load at all, depending, as has been stated, upon the location of the axis of the rockshaft. This reduction or total elimination of the load enables the motor to start and to et up peed partially or wholly free from load, and therefore a motor of low starting torque may be employed. v

As herein shown, the eccentric'ity'of the rockshaft BI and the corresponding eccentricity of the crank-pin 33 are governed by a centrifugal governor, which is responsive to variations in the speed of the motor. This is conveniently accdmplished by mounting on the rockshaft a centrifugal weight 62 (best shown in Fig. 6), herein formed as an integral part cf the rockshaft. The turning movement of the rockshaft in opposite directions is limited by suitable means, such as a stop-screw 63, having a reduced portion 64 which is received in a segmental groove 65 in the rockshaft.

While the weight 62 might be relied upon without other "aid to control the turning of the rockshaft under the influence of variation in the speed of the motor, I prefer to employ a spring 66 to assist the weight. As herein shown, this spring is arranged to have a neutral position, in which it is not stressed, and in which position the stop-screw 63 (see Fig. 6) is in the center of the segmental slot 65 when the machine is at rest. This is simply a matter of securing .the ends of the spring in the desired relationship to the parts which they connect. As shown in Fig. 2, one end of the spring is wound about and secured to a plug 61, having a tongue 68, which is received in a slot 69 in the shaft 36, and the other end of the spring is wound about and 4 cured to a similar plug 10, having a tongue ll eceived in a slot 12 in the rockshaft 6!. As herein shown, these slots are conveniently formed by making drilled,

holes, into which the tongues extend laterally. In the present example, the rockshaft is mounted in an eccentrically disposed bore 13 in the shaft 36, and the spring 66 is disposed in a bore I4 within the rockshaft.

In order that the rotating parts shall be in balance after full speed of the motor is attained, I provide the rotatable shaft 36 with a fly-wheel 15, having a weight 16 which is opposite to the weight 62 when the latter is fully advanced. This ensures smooth running, without noticeable vibration, as the two weights under this condition constitute together a balanced fly-wheel.

The operation of the unloading mechanism will not be described in detail, because it forms no part of the present invention, except in so far as it is related to the oiling system presently to be described. It will sufiice to say that in the initial position of the crank-pin, when the parts are at rest, the crank-pin has a slight throw, or its axis may be coincident with the axis ofthe rotatable shaft in which position it has no throw atall. When the motor starts and as its speed increases, the eccentricity of the crank-pin increases, until in the full running position shown position, instead of to its position of minimum throw. When the motor starts, the weight 62 Will by its inertia lag behind the shaft 36, and will thus bring the crank-pin momentarily to its minimum throw, in opposition to the resistance of the spring. When, however, the shaft acquires sufficient speed, the centrifugal effect of the weight, due to its eccentric mounting, results in the weight being thrown outwardly with relation to the shaft. During the first half of this movement, the spring, which is under stress, assists the weight in moving outwardly with relation to the shaft.

As the speed of the shaft increases, the weight carries the rockshaft and the crank-pin past the neutral position of the spring, and thereafter the spring is stressed in the opposite direction, and yieldingly resists outward movement of the weight. When the weight, the rockshaft and the crank-pin reach their extreme outward position,

the crank-pin has its greatest throw and the piston its greatest stroke.

When the current is cut oif from the motor and the speed of the shaft is reduced, the weight commences to lag behind the shaft, and is assisted by the spring during the first half of this backward movement with relation to the shaft. During this time, the throw of the crank-pin is reduced, the stroke of the piston is correspondingly decreased, and the load on the motor is in two, lateral ports 99 (which merely for con venience of manufacture are made separate instead of as a slot), which are brought into registration with the port I9 in the cylinder during the movement of the piston. The; lower portion of the chamber 32, or crank-case; constitutes an oil reservoir in which a body of oil is maintained at some such level as that shown in Fig. 2, well above the upper end of the cylinder 18. At this point, it is to be understood that the weight 62 and the fiy-wheel 15 with its weight 16, in tuming, splash oil about in the chamber 32, and provide additional assurance of lubrication of all running parts within thechamber, thus supplementing the circulating pressure feed.

In the position of the oil pump piston shown in the drawings; one of its ports 89 is'in registration with the port 19 in the cylinder 18, thus providing a path for the entrance of oil from the reservoir into the space within the hollow piston 11, and into a chamber 8| below and in communication with the interior of the piston. During the downward stroke of the piston toward the end of its travel, the port 19 in the cylinder 18 is closed, whereupon the piston produces a pressure within itself and within the chamber 8|. Referring now to Fig. 9, there is a horizontal out-- let passage 82 from this chamber, formed partly in the cylinder 18, partly in the housing 3|, and partly in the cover-plate 38. This passage communicates with an upwardly-extending passage 83 (see Fig. 4) which in turn communicates with an annular chamber 84 in the'bearing 31, thus providing a considerable amount of oil about the shaft 36, and 'lesseningthe adhesion of the shaft to the bearing, thereby offering less resistance at the moment or starting the shaft in rotation.

This chamber, in turn, communicates with pairs of grooves 85 and 85 (best. shown in Fig. extending lengthwise of the bearing.

The grooves 85 (see left-hand end of Fig. 10) lead directly back into the chamber 32. The grooves 85 communicate with an annular groove 86 in the bearing 31 about the shaft adjacent the end of the bearing, and continue past said annular groove to the adjacent face of the thrust washer 99. To assure lubrication of the bearing surface of the thrust washer against the end of the bearing 31, the thrust washer (see Fig.5) is provided with one or more, herein two angular grooves 81, which draw oil out of the grooves 85' and feed it to the endwise engaging surfaces. a Any oil which escapes at this point into the motor chamber 39 gravitates into a groove 88 at the bottom of the chamber, and is sucked up by the gas intake pipe 58, which, as herein shown, is provided with a wire gauze strainer 89 about its lower end. The oil which is sucked up by the gas intake conduit passes upwardly along with the gas, and is returned to the chamber 32, by way of the recess 51 (see Fig. 3). At this point, there is a slot 99 leading downwardly from the recess 51 into a passage 9I to restore oil to the annular chamber 89. This supplements the supply of oil which is pumped around-through the circulating system. Referring now to Fig. 2, lubrication of the bearing surfaces of the rockshaft is accomplished by taking oil from the annular chamber 89 through openings 92 and also from the annular groove 85 through the slot 69 to the bore 13, in which therockshaft 95 turns in the driving shaft 36.

It will be remembered that the gas which is withdrawn from the motor chamber into the suction chamber of the pump enters the suction chamber through the passage 56. Before this gas can pass upwardly into the passage 58 (see Fig. 6), it must pass downwardly beneath the lower edge of a vertically disposed baffle 93, and thence upwardly to the passage 58. This baflie tends to return to the bottom of the chamber 32 oil carried by the gas.- An additional baffle 98, which is closed at its outer end (see Fig. 7) and is disposed beneath the passage 58, guards the latter against the entrance of oil which might otherwise be carried in that direction by the splash and the rotation of the weights 62 and 16. Another obliquely disposed bafiie 95, opposite the baflie 94, prevents oil from being carried over into the space between the baflies 94 and 95 by the rotation of the weights, which is in the direction of rotation of the arrow-i. e., clockwise. Oil caught by the baflie 95 turns back to the main body of oil, while the machine is in operation, and when it is idle. The baflies 93, 94 and 95, are conveniently made as a unit, shown in Fig. 7, with the baffle 93 in the form of a fiat plate welded or otherwise appropriately secured to two arc-shaped pieces 96 and 91, on which the baffles 94 and 95, respectively, are formed. The arcshaped piece 95 is provided with an opening 98, which registers with the passage 59 (see Fig. 6),

and this opening has about it a lip 99, which tends to prevent the entrance of oilinto the passage 58. In assembling the machine, the

baffle unit shown in Fig. 7 is fitted into the chamber 32, and the parts 96 and 91 snugly fit the cylindrical surface of the chamber.

In addition to themeans of lubrication afforded by the described circulating system and by the oil sucked up by the gas intake, there is a rather elaborate splash system which will now be described, reference being bad at first to Fig. 2. The upper end ofthe hollow oil pump piston 11 is provided with an opening I99, through which oil is splashed upwardly onto the lower bearing surface of the sliding shoe or cross-head 34, and from this point, oil is distributed along the lower face of the shoe by radiating grooves I9I (see Fig. 8). Oil also passes through a passage I92 leading upwardly to the bearing surface of the crank-pin, and through a radial passage I93 in the latter to a longitudinal passage I 94, which communicates with the bore 14 within the rockshaft GI.

The compressor piston is lubricated by splash and mist, and the piston is provided with an opening I95 to conduct oil to its interior, whence oil gravitates through an opening I 96 in the piston to a passage I91 in the sliding shoe or cross-head 39, whence oil is conducted to the bearing surface of the crankpin. The opening I96 also feeds oil to the upper bearing surface of the sliding shoe, and this oil is distributed by radiating grooves I98 similar to the grooves I9I over the sliding surfaces. The crank-pin is additionally lubricated by splash through upper and lower openings I99 provided in a hub-like extension'l I9 of the sliding shoe. Distribution of oil lengthwise of the crank-pin is eifected by grooves III (see Fig. 6), formed in the shoe lengthwise of the crank-pin. Instead of providing the compressor piston with rings, the latter is provided with a series of circumferential oil grooves 2, which serve to form an oil seal sponding recess in the housing 3|. The diameter of the cylinder 18 is such that by first removing the cylinder head 3 and then the cylinder 18, the piston member, comprising the compressor piston and the oil pump piston, can be removed downwardly after being disconnected from the crank-pin by first removing the partition plate 38 with its bearing and the parts carried thereby. This of course calls for the preliminary removal of the cover-plate 40, and then the stator 43%, before the partition plate 38 can be removed.

' It will thus be seen that the oiling system comprises first, a circulating system including the oil pump, second, a splash system, utilizing the splash of oil due to the motion of the mechanism in the chamber 32, and, third, the utilization of the gas suction pipe as a means for ridding the motor chamber of oil and utilizing this oil to supply some of the bearing surfaces. In all, the lubricating system is unusually complete and adequate to furnish'ample lubrication to all working parts.

Having thus described one embodiment of the invention, but without limiting myself thereto, what I claim and desire by Letters Patent to secure is:--

1. A gas compressor and motor unit comprising, in combination, a housing presenting a motor chamber and a crank-case andsuction chamber with a partition therebetween, said motor chamber having an inlet for the gas, and said partition having a passage for gas and lubricating oil from said motor chamber to said crankcase and suction chamber, said crank-case and suction chamber presenting a reservoir for lubricating oil, a compressor cylinder having a lateral, refrigerant intake port leading from said crank-case and suction chamber into said cylinder, a compressor piston working in said cylinder and covering and uncovering said port, an oil pump cylinder having a lateral, oil intake port leading from said oil reservoir into said oil pump cylinder, an oil pump piston working in said oil pump cylinder and covering and uncovering said oil intake port, an electric motor housed within said motor chamber, a crank housed within said crank-case and suction chamber, a driving shaft connecting said motor to said crank-pin to drive the latter, a bearing for said shaft supported by said partition and provided with an oil chamber about said shaft and a passage leading from said oil chamber to said crank-case and suction chamber, an oil supply conduit leading from said oil pump. cylinder to said oil chamber, and baflle means to cause the separation of the oil from the gas within said crank-case and-suction chamber .and the return of the oil to said oil reservoir.

2. A gas compressor and motor unit comprising, in combination, a housing presenting a gas intake chamber and an oil reservoir, 2. gas compressor whose intake is in communication with the upper portion of said chamber, an oil pump whose intake is in communication with the lower portion of said chamber, a common driving mechanism for said compressor and said oil pump, a motor which drives said mechanism, said mechanism and said motor being housed within said housing, and means to conduct oil'from said pump to said driving mechanism and to rewhich drives said mechanism and a housing which houses-said'mechanism and said motor presenting a gas intake chamber for said compressor and an oil reservoir from which said oil pump takes oil and supplies oil to said driving mechanism, said cylinder and a portion of said piston being within said oil reservoir where they the engaging surfaces of said bearing and said thrust washer, and means to cause the distri-- bution of oil on said surfaces.

5. A compressor unit comprising, in combination, a compressor for the gas, an oil pump, a common driving shaft for said compressor and said pump, a bearing for said shaft, a thrust washer carried by said shaft and engaging said bearing endwise, means to conduct oil from said pump to the engaging surfaces of said washer and said bearing, and an electric motor comprising a stator and a rotor, the latter being secured to said shaft and offset with relation to said stator in a direction opposite to said bearing to utilize the magnetic flux to urge said washer against said bearing.

6. A gas compressor and motor unit comprising, in combination, a sealed unit comprising a gas compressor having an intake chamber, a motor chamber having a gas inlet, an electric motor within said motor chamber, a driving mechanism including a shaft connecting said motor and said compressor, a bearing for said shaft, a circulatory oiling system including an oil pump which supplies oil to the bearing surfaces of said shaft and said bearing, and a gas and oil suction conduit leading from said motor chamber and delivering gas from said motor chamber to said intake chamber and oil from said motor chamber to said oiling system.

7. A gas compressor and motor unit comprising, in combination, a sealed unit comprising a gas compressor having an intake chamber, a motor chamber having a gas inlet, an electric motor within said motor chamber, a driving mechanism including a shaft connecting said motor and said compressor, a bearing for said shaft, a circulatory oiling system including an oil pump which supplies oil to the bearing surfaces of said shaft and said bearing, and a gas and oil suction conduit leading from said motor chamber and delivering gas from said motor chamber to said intake chamber and oil from said motor chamber to said oil pump.

8. A gas compressor and motor unit comprising, in combination, a sealed unit comprising a gas compressor having an intake chamber, a motorchamber having a gas inlet, an electric motor within said motor chamber, a driving mechanism including a shaft connecting said motor and said compressor, a bearing for said shaft, a circulatory oiling system including an oil pump which supplies oil to the bearing surfaces of said shaft and said bearing, said pump being disposed Within said intake chamber, and a gas and oil suction conduit leading from said motor chamber and delivering gas from said motor chamber to said intake chamber and oil from said motor chamber to said oiling system.

which supplies oil to the bearing surfaces of said shaft and said bearing, said pump being disposed within said intake chamber and driven by said shaft, and a gas and oil suction conduit leading from said motor chamber and delivering gas from said motor chamber to said intake chamber and oil from said motor chamber to said oiling system.

;10. A gas compressor and motor unit comprising, in combination, a sealedunit comprising a A gas compressor having an intake chamber, a motor chamber having a gas inlet, an electric inotor within said motor chamber, a driving mechanism including a shaft connecting said motor and said compressor, a bearing for said shaft, a circulatory oiling system including an oil pump which supplies oil to the bearing surfaces of said shaft and said bearing, and a gas and oil suction conduit leading from said motor chamber and delivering gas from said motor chamber to said intake chamber and oil from said motor chamber to said bearing surfaces.

11. In a compressor unit, the combination of a compressor comprising a cylinder and a hollow piston working therein, said piston having one or more lateral openings leading thereinto to supply oil to the interior of said piston and an opening through which oil is conducted from the interior of said piston, and mechanism to drive said piston, said mechanism including a crankpin supplied with oil from the interior of said piston.

12. In a compressor unit, the combination of a gas compressor having a gas intake chamber the lower portion of which constitutes an oil reservoir, means to deliver gas and oil to said chamber, and means within said chamber to separate oil from the gas and to permit oil to gravitate into said reservoir.

13. In a compressor unit, the combination of a gas compressor having a gas intake chamber the lower portion of which constitutes an oil reservoir, means to deliver gas and oil to said chamber, and a bafilewithin said chamber to cause oil to be separated from the gas and allowed to gravitate into said chamber.

1%. In a compressor unit, the combination of a gas compressor comprising a gas intak chamber A the lower portion of which constitutes an oil reservoir, said compressor comprising a cylinder having a lateral intake port, and a piston working in said cylinder and covering and uncovering said port, and means within said chamber to deflect oil from said port.

15. In a compressor unit, the combination of a gas compressor comprising a gas intake chamber the lower portion of which constitutes an oil reservoir, said compressor comprising a cylinder having a lateral intake port, and a piston working in said cylinder and covering and uncovering said port, and a plurality of baifies within said chamber to deflect oil from said port.

16. In a compressor unit, the combination of a gas compressor comprising a gas intake champort.

3 ing in said cylinder and covering and uncovering said port, mechanism to drive said piston, said mechanism including a part rotating with in said chamber, and a baiile within said chamber and arranged to guard said port from oil thrown off by said rotating part.

17. In a compressor unit, the combination of a gas compressor having a gas intake chamber the lower portion of which constitutes an oil reservoir, said compressor having an intake port leading from said chamber, means to conduct gas and oil into said chamber, and means to cause oil entering said chamber to be directed downwardly into said reservoir while allowing gas free from oil to enter said intake port. I 18. In a compressor unit, the combination of a gas compressor having a gas intake chamber the lower portion of which constitutes an oil reservoir, said compressor having an intake port leading from said chamber, means to conduct gas and oil into said chamber, and a baffle extending downwardly below said intake port to cause oi and gas entering said chamber to be directed downwardly and the oil allowed to gravitate into said reservoir while the gas rises to said intake 19. A gas compressor unit comprising, in combination, a compressor for the gas, an oil pump comprising an oil displacing member and a chamber from which said member displaces oil, a common driving mechanism for said compressor and said member, said mechanism including a driving shaft and a bearing for said shaft, a housing presenting a gas intake for said compressor and an oil reservoir from which said chamber receives oil, and a conduit disposed externally of said member and leading from said chamber directly to bearing surfaces of said bearing and said shaft.

20. A gas compressor unit comprising, in combination, a compressor for the gas, an oil pump comprising an oil displacing member and a chamber from which said member displaces oil, a common driving mechanism for said compressor and said member, said mechanism including a driving shaft and a bearing for said shaft, said bearing being provided with a reservoir about said shaft, a housing presenting a gas intake chamber for said compressor and a main reservoir from which said chamber receives oil, and a conduit disposed externally of said member and leading from said chamber directly to the first-mentioned reservoir.

21. A gas compressor unit comprising, in combination, a compressor for the gas, an oil pump comprising an oil displacing member and a cham-.

ber from which said member displaces oil, a common driving mechanism for said compressor and said member, said mechanism including a driving shaft and a bearing for said shaft, said bearing having an end thrust-receiving surface, a housing presenting a gas intake for said compressor and an oil reservoir from which said chamber receives oil, and a conduit disposed externally of said member and leading from said chamber to said thrust-receiving surface.

22. A gas compressor unit comprising, in combination, a compressor for the gas, an oil pump comprising-an oil displacing member and a chamber from which said member displaces oil, a common driving mechanism for said compressor and said member, said mechanism including a drivleading from said reservoir to said surface, a housing presenting a gas intake for said compressor and an oil reservoir from which said chamber receives oil, and a conduit disposed externally of said member and leading from said chamber to the first-named reservoir.

23. A gas compressor unit comprising, in combination, a compressor for the gas, an oil pump comprising an oil displacing member and a chamber from which said member displaces oil, a. common driving mechanism for said compressor and said member, said mechanism including a driving shaft and a bearing for said shaft, said bearing being provided with a reservoir about said shaft, thrust-receiving surfaces and conduits leading from said reservoir in opposite directions to said surfaces, a housing presenting a gas intake for said compressor and an oil reservoir from which said chamber receives oil, and a conduit disposed externally of said member and leading from said chamber to the first-named reservoir.

WILLIAM D. DRYSDALE. 

